The use of tissue culture system in setting up model systems has been and will continue to be an important aspect in the Viral Oncology Program to study the possible role of viruses in the etiology of human cancer. The purpose of this project is to provide for maintenance of a facility which rapidly and successfully responds to the needs of investigators for characterization and identification of many diverse cell lines. This is to establish purity and species of origin. These tasks will require biochemical (isozyme), immunological (including immunofluorescent), and chromosomal analysis in various combinations.